Substrate supporting rod and substrate cassette using the same

ABSTRACT

A substrate-supporting rod ( 4 ) comprises a resin body ( 41 ) and a metal rod ( 43 ). The resin body ( 41 ) includes a body portion ( 411 ) being cylinder-shaped and having a first through hole ( 413 ) in a direction of the axis thereof and a number of shelves ( 415, 415 ′) arising from said body portion ( 411 ) and extending in parallel and inwardly of a cassette ( 5 ) at a predetermined pitch. The metal rod ( 43 ) is received in the first through hole ( 413 ) of the body portion ( 411 ) so as to increase the rigidity of the substrate-supporting rob ( 4 ). A projection ( 4151 ) is defined on the end of each shelf ( 415, 415 ′) to support a substrate ( 45 ). Further, the body portion ( 411 ) is molded from an electrically conductive resin so that not only the cassette ( 5 ) can be protected against static discharge but also resin material is saved and cost is decreased.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cassette for accommodating aplurality of substrates in mutual isolation. The invention furtherrelates to a substrate supporting rod which is to be a functional memberof said cassette.

2. Description of Related Art

Substrates such as glass substrates must be stored and taken out from acassette in such a manner that the plural substrates will not contactwith each other.

The cassette in common use comprises a box-shaped resin frame equippedwith pairs of opposed resin side members each formed with grooves sothat one and each substrate may be accommodated between grooves of theopposed side boards.

JP H 08-021612 discloses a cassette comprising a plurality ofsubstrate-supporting boards 2 including a body 21 and a plurality ofshelf members 22 extending in parallel from the body 21 at apredetermined pitch as illustrated in FIG. 1 and FIG. 2. The shelfmember 22 comprises a first shelf 22X extending inwardly of the cassetteand a second shelf 22Y extending outwardly of the cassette. In addition,a projection 23 is provided on the end of the first shelf 22X of whichthe highest portion is smooth curve surface. Although the projection 23for supporting a substrate B leads to a decrease of dusts of frictionbetween edges of the substrate B and the substrate-supporting board 2,the problem of static discharge can not be solved. Otherwise, for thesubstrate-supporting board 2 is a structure of board, not all parts ofthe first shelf 22X can be used for supporting the substrate B.Therefore, it is a waste of material on design.

Referring to FIG. 3, another conventional cassette disclosed in the U.S.Pat. No. 5,584,401 has a plurality of substrate-supporting side boards 2comprising a metal core M, an overlay 21 and a plurality oftongue-shaped shelf members 22, at least the frontal part of saidoverlay and the shelf members being made of resin, and at least arib-like projection 3× extending centrally and longitudinally from theoverlay being molded from a dust-inhibited resin molding material, withthe remainder being molded from an electrically conductive resin moldingmaterial. Although said cassette is protected against static dischargein the insertion and removal of substrates and is not liable to formdusts such as the dust of friction due to friction against substrates,its whole structure is complex so that the cost of the fabrication ishigh.

Therefore, it is desirable to provide a cassette which both savesmaterial and inhibits static discharge in the insertion and removal ofsubstrates.

SUMMERY OF THE INVENTION

One objection of the present invention is to provide a substratesupporting rod which is able to retrench material during fabrication.

Another objection of the present invention is to provide asubstrate-supporting rod which not only retrenches material but also canbe protected against static discharge.

The third objection of the present invention is to provide a cassetteutilizing a plurality of the substrate-supporting rods saving material.

The last objection of the present invention is to provide a cassetteutilizing a plurality of the substrate-supporting rods which both savematerial and inhibit static discharge.

In order to achieve the objections set forth, a substrate-supporting rodenclosure in accordance with the present invention comprises a resinbody and a metal rod. The resin body includes a body portion beingcylinder-shaped and having a first through hole in a direction of theaxis thereof and a number of shelves arising from said body portion andextending in parallel and inwardly of a cassette at a predeterminedpitch. The metal rod is received in the first through hole of the bodyportion so as to increase the rigidity of the substrate-supporting rob.A projection is defined on the end of each shelf to support a substrate.Further, the body portion is molded from an electrically conductiveresin so that not only the cassette can be protected against staticdischarge but also resin material is saved and cost is decreased.

The detailed features of the present invention will be apparent in thedetailed description with appropriate reference to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a conventional substrate-supporting board;

FIG. 2 is side elevational view of said substrate-supporting board ofFIG. 1;

FIG. 3 is a perspective view of the substrate-supporting side boards ofanother conventional cassette;

FIG. 4 is a perspective expoded view showing a typicalsubstrate-supporting rod according to the invention;

FIG. 5 is a schematic diagram showing the substrate-supporting rodcooperating with a substrate, in which a shelf of thesubstrate-supporting rod is perpendicular to the axis of a body portion;

FIG. 6 is a schematic diagram showing the substrate-supporting rodcooperating with a substrate, in which a shelf of thesubstrate-supporting rod is slant relative to the axis of the bodyportion;

FIG. 7 is a perspective view of a cassette according to the invention;and

FIG. 8 is a schematic diagram illustrating the substrate-supporting rodconjugating with a frame.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is now described in detail.

Referring to FIG. 4, a substrate-supporting rob 4 according to thepresent invention comprises a resin body 41 and a metal rod 43. Theresin body 41 includes a body portion 411 being cylinder-shaped having afirst through hole 413 in a direction of the axis thereof and a numberof shelves 415 arising from said body portion 411 and extending inparallel and inwardly of a cassette 5 at a predetermined pitch. Thecross section of said body portion 411 is C-shaped in order to savematerial, while the cross section of said body portion 411 designed asbeing O-shaped is viable. The metal rod 43 comprises a pair of endportions 431 each of which having a pair of side faces (not labeled)parallel to each other and a threaded hole 433. The metal rod 43 isreceived in the first through hole 413 of the body portion 411 so as toincrease the rigidity of the substrate-supporting rob 4.

Referring to FIG. 5, a receiving passageway 417 is formed between everyadjacent shelves 415 of said rod 4 to accommodate a substrate 45. And aprojection 4151 extends from the free end of each of the shelves 415 forsupporting a substrate 45. The projection 4151 is disposed as a shape ofcylinder of which the diameter is larger than the thickness of the shelf415, while only the highest portion of said projection 4151 being asmooth curve surface is certainly feasible. Furthermore, not only eachof the shelves 415 can be disposed perpendicularly to the axis of thebody portion 411 but also the shelf 415′ can be configured at an upwardinclination with respect to the axis of the body portion 411 asillustrated in FIG. 6.

In addition, the shelves 415 only extend from one side of the bodyportion 411. As a result, the above construction leads to decrease ofmaterial and cost. Further, in accordance with the present invention,only the projection 4151 contacts with the bottom of the substrate 45while the substrate 45 is being inserted into or removed off thecorresponding receiving passageways 417, that is, edges of the substrate45 don not contact with the shelf 415 or the body portion 411. The aboveconstruction of the projection 4151 leads to a marked decrease in dustsof friction at insertion or removal of the substrate 45.

The body portion 411 is molded from an electrically conductive resin,which is a dispersion of a particulate electrically conductive substancein a matrix resin. The electrically conductive substance includes but isnot limited to carbon fiber and carbon powder. On the other hand, themetal rod 43 may for example be aluminum or stainless steel. Therefore,the substrate-supporting rod 4 can be protected against staticdischarge.

Then, referring to FIG. 7, the cassette 5 comprises a pair of frames 51configured with at least two pairs of substrate-supporting rods 4 in theoverall shape of a box for accommodating a substrate 45 between theshelves 415 of each opposed pair of the rods 4. The frame 51 illustratedin FIG. 8 is provided with several grooves 511 on each of which a secondthrough hole 513 is disposed. The groove 511 includes a pair of sidefaces parallel to each other, between which the distance is comparativeto that between the pair of side faces of end portion 431 of the metalrod 43. The substrate-supporting rod 4 is secured on the frame 51 byinsertion of the end portion 431 into the groove 511 so as to preventingthe metal rod 43 from rotating with respect to the frame 51 and furtherby a bolt combination with the threaded hole 433 of the metal rod 43through the second through hole 513 on the frame 51. Furthermore, toprevent the resin body 41 from rotating relative to the metal rod 43,another bolt is introduced.

To sum up, according to the present invention, the substrate-supportingrod 4 of the cassette 5 is cylindrical in shape different from thecommon structure of board so that resin material is saved and cost isdecreased. Further, the body portion 411 is molded from an electricallyconductive resin so that the cassette 5 can be protected against staticdischarge.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present invention have been setforth in the foregoing description, together with details of thestructure and function of the invention, the disclosure is illustrativeonly, and changes may be made in detail, especially in matters of shape,size, and arrangement of parts within the principles of the invention tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed.

1. A substrate-supporting rod to be assembled with a cassette frame forsupporting substrates comprising: a resin body which comprises acylindrical body portion having an axial first through hole and a numberof shelves arising from said body portion and extending in parallel andinwardly of the cassette at a predetermined pitch; and a metal rod beingreceived in said first through hole of the body portion.
 2. Thesubstrate-supporting rod according to claim 1 wherein said body portionis molded from an electrically conductive resin molding material.
 3. Thesubstrate-supporting rod according to claim 1 wherein each of theshelves is provided with a projection extending from a free end thereof.4. The substrate-supporting rod as claimed in claim 3, wherein saidprojection is cylindrical in shape of which the diameter is larger thanthe thickness of the shelf.
 5. The substrate-supporting rod as claimedin claim 3, wherein said projection comprises a highest portion having asmooth curved surface.
 6. The substrate-supporting rod according toclaim 1 wherein each of the shelves extends perpendicularly to an axisof the body portion
 7. The substrate-supporting rod according to claim 1wherein each of the shelves is upward inclined relative to an axis ofthe body portion.
 8. The substrate-supporting rod according to claim 1wherein the cross section of said body portion is C-shaped.
 9. Thesubstrate-supporting rod according to claim 1 wherein the cross sectionof said body portion is O-shaped.
 10. The substrate-supporting rodaccording to claim 1 wherein the metal rod comprises a pair of endportions each of which having a pair of side faces parallel to eachother and a threaded hole.
 11. A cassette for supporting substratescomprising: at least two pairs of substrate-supporting rods, each rodcomprising: a resin body which comprises a cylindrical body portionhaving an axial first through hole and a number of shelves arising fromsaid body portion and extending in parallel and inwardly of the cassetteat a predetermined pitch; and a metal rod being received in said firstthrough hole of the body portion; and a pair of frames cooperating withthe substrate-supporting rods in the overall shape of a box foraccommodating a substrate between the shelves of each opposed pair ofrods.
 12. The cassette as claimed in claim 11, wherein said body portionis molded from an electrically conductive resin molding material. 13.The cassette according to claim 11 wherein each of the shelves isprovided with a projection extending from a free end thereof.
 14. Thecassette according to claim 13 wherein said projection is cylindrical inshape of which the diameter is larger than the thickness of the shelf.15. The cassette according to claim 13 wherein said projection comprisesa highest portion having a smooth curved surface.
 16. The cassetteaccording to claim 11 wherein each of the shelves extendsperpendicularly to an axis of the body portion
 17. The cassetteaccording to claim 11 wherein each of the shelves is upward inclinedrelative to an axis of the body portion.
 18. The cassette as claimed inclaim 11, wherein the cross section of said body portion is C-shaped.19. The cassette as claimed in claim 11, wherein the cross section ofsaid body portion is O-shaped.
 20. The cassette as claimed in claim 11,wherein the metal rod comprises a pair of end portions each of whichhaving a pair of side faces parallel to each other and a threaded hole.21. The cassette as claimed in claim 11, wherein each of the frames isprovided with several grooves, each of which matches with the endportion of the metal rod.
 22. The cassette as claimed in claim 21,wherein each of the groove is provided with a second through holesecured with the threaded hole of the end portion of the metal rod. 23.A substrate-supporting rod to be assembled with a cassette frame forsupporting substrates comprising: a body which comprises a body portionhaving a first elongated axial section and a number of shelves arranged,at a predetermined pitch, along an axial direction of said body portionand extending from said body portion in parallel and inwardly of thecassette; and a reinforced rod defining a second elongated axial sectionengaged with said first elongated axis section without relative movementtherebetween in a lateral direction perpendicular to said axialdirection.